After dozing off contentedly in the backyard hammock last week, a rousing avian chorus in the woods woke me from my slumber. Even in my bleary state, I managed to identify a half-dozen different tunes being chirped almost simultaneously, not counting the irritating calls of the neighborhood's weed-wacker warblers and lawnmower loons.

Rock bands playing 80- or 90-minute shows these days get applauded by fans for their stamina. Believe me, that's nothing compared to the singing endurance of a blackbird, rose-breasted grosbeak or Baltimore oriole, and by oriole, I'm not talking baseball iron-man Cal Ripken.

Anyway, I couldn't help but wonder what prompts these rappers of the wild to show off their versatile vocal stylings (especially at full throttle at 6 a.m. on weekend mornings when they must know I'm trying to sleep in).

Turns out, it's sex.

Well, that's the overriding motivation anyway, according to Steve Minard, 57, of East Grand Rapids, a Grand Rapids Audubon Club member who has observed and listened to birds for 33 years.

"The two biggest reasons are to defend a territory, telling other birds, 'This is my territory and stay out, unless you're a cute female who wants to visit me,' which is the second reason," Minard said. "And frankly, the territorial part is somewhat sex, too, because they're trying to have a good territory to raise their young."

The bottom line: Outside of warning calls when a predator is approaching, most of that beautiful racket you hear is all about impressing the opposite sex. That sure sounds an awful lot like rock 'n' roll to me.

This is certainly true of Australia's incredible lyrebird, which literally can imitate the songs of 20 or 30 other bird species to get attention, sort of like a rock cover band playing other groups' greatest hits at a singles bar. In one of several YouTube videos I found online, BBC broadcaster and naturalist David Attenborough said that "to persuade females to come close and admire his plumes, he sings the most complex song he can manage and he does that by copying the songs of all the other birds he hears around him." (Think "leather-clad lead singer in a bar band.")

More remarkably, this feathered creature can perfectly mimic mechanical devices such as camera shutters, car alarms, even chainsaws, though I'm not sure how that might help in attracting a cute chickadee unless she's fond of lumberjacks and paparazzi. The lyrebird apparently can even replicate music and the mindless chatter it hears on the radio, which I figure may actually be a turn-off in that lure-the-opposite-sex thing.

YouTube is also where I found an eerie recording of "Symphony of the Birds," created in the 1950s by Jim Fassett, who must have spent countless hours recording, then combining, bird chirps and wails and whoops to compose a creepy-sounding piece of music.

As one YouTube commenter with a too-vivid imagination put it, "I couldn't fall asleep to this. I would think the world is ending from a large UFO beaming over my town (with) little aliens coming out and capturing my brain." Then again, birds might say the same thing about death metal or Justin Bieber, I suppose.

But the truth is, human "composers have definitely used bird songs for inspiration" over the centuries, Minard said. This includes classical pieces as well as modern pop songs. Pop/rock innovator Kate Bush's 2005 masterpiece "Aerial" featured lengthy segments of birds singing interspersed with her own music.

Comstock Park fiddle-master Bruce Ling, a longtime Grand River dweller who even named his acoustic folk band after some bird species, Hawks & Owls, frequently plays an old fiddle tune, "Dubuque," with a passage that mimics the call of a chickadee. Even poultry can be an inspiration.

"I just wrote a chicken song as a matter of fact," Ling, 53, said of his tune, "Chicken Tractor," which features a clucking sound produced by his fiddle.

Still, I'm guessing nothing concocted by a human could probably ever match the sheer natural beauty and raw talent of a lyrebird or a mockingbird, or even a house wren.

I even found video footage online of an absolutely astounding cockatiel that literally sings the blues to music played by his master on piano. Now, if that doesn't impress the ladies, nothing will.